Hexachlorothiolene



Patented Apr. 11,. 1950 HEXACHLOROTHIOIJENE.

Henry D. Norris, Woodbury, N. J'., and John H1. McCracken; Corpus Christi, Tex, asslgnorsto Socony-V'acuum Qil Company; lncorporatedg. a. corporation of? New York No;Drawing;. Application May 10, 1.947; Serlal No. 747,328

7 Claims. 1.

In copending. application Serial No. 613;. 02; filed. August 28,..1945,v now' abandoned, of which the present application is a continuationwin-part, there: is; described 8; process: involving, complete chl'orniatiorr-ofi. thi'ophene'. The present invention relates to a. new composition producedrby complete chlorinaticnzofi thiophene in the presenceof iodlneras; catalyst. and; more particularlv, is con.- cerned. with a. catalytic: processv for effecting the complete: chlorination of thiophene: to produce hexachlorothiolene. I

Chlorination-is a, term. well known in the art and when appliedto hydrocarbons ordinarily'connotes the direct substitution of a. chlorine atom for a hydrogen atom. The chlorination may be carried to such. an. extent that allthe hydrogen atomsiofl a hydrocarbon may; berepla-cedbychlorine; atoms. This. is referred. tointheart. asscomplet'e chlorination. It hasbeen discovered, in. ac.- cordanceiwith the present. invention, that when thiophene subjected tocomplete chlorination in the presence of a small amountof: iodine, the chlorinated product includes 9,. compound, which contains an amount of. chlorine in. excess. of; the amountwhich accounts. for the. expected and ordinary total. chlorination, of the thiophenev nu.- clei. or the complete replacement of the 4 hydrogen atoms in the thiophenenuclei.

It has been found, asset-forth hereinaftenthat when thiophene is subjected to complete chlorination. in the presence ofiodine, hexachlorothiolene is obtained. This, new composition of. matter is a useful lubricating oil addition, agent particularly adapted for use as. an additive. in extreme pressure, lubricants. Moreover, as. those skilled; in the, art will recognize, the new compound of tllisinvention, by reason of, the high activity of'its chlorine. atoms, will serve as a useful chemical intermediate in the synthesis of further new compositions;

Accordingly; it is an object of the present inventiontoprovide anew composition of matter. Another object is to provide hexachl'oroth-iolene. A further impotrant object is to provide a lubricating, oil addition agent; A further object is to provide a lubricating oil composition. A more specific object is to: aiford a. process for-manuface turing hexachlorothiolene. Other objects and; advantages of the present invention willbecome parenttothose. skilled. in the art from the. fol.- lfowingdescription.

Broadly stated, the present invention provides a new composition of matter, hexachlorothlolene; a new addition agent for lubricating oils; and a method for preparing hexachlorothiolene, which comprises contacting. thiophenewith chlorine in the presence of an iodine catalyst under conditions for efiecting, complete chlorination.

Hexachlorothiolene is a colorless substance having a melting point of 40.5-41. C. and a boiling point of 90.5-91.50. at a pressure of2 millimeters of, mercury. It is stable up to a temperature of about 225 C .,v above which the compound. tends to,v decompose into chlorine and various p013;- chlorothiophenes, hexachlorothiolene has. anon; sity of 1.753 at 26.5 C. compared to that of water at 4 C. and a refractive index at 20 C. of 1.58.78.

The. formula. of hexachlorothiolene is, 643616. The hexachlorothiolene: Obtained in accordance with the present invention has the following analysis:

' Analysis: Theoretical:

Per Per Cent? Ohlorinc 72. 47 v 72,? Sulfur 10.=92= 10:91 Garbon 16:49 163 41 In infra-red absorption: spectra studyof the compound showed that. it; had, lost: all. characteristicsof thiopheneand a definite. absorption band for an olefinic linkage appeared. Further evidence that the compound. or this mvention. was hexachl'orothiolene was. shown. by reaction of the compound with. zinc dust... As. is well known tothose skilled in. the. art; dihalogen compounds of the nature -CHCl- -CHCl:.-e dehalogenat'e upon. treatment with zinc. dust: to produce. olefins. The compound of. this invention, upon treatment. with zinc. dust, gave, aproduct mixture which analysis: showed to contain. a small amount of dichlorothiophene, a small amount or tri'chlorothiophene, and about per" cent of 2,3,4,5;-te tra.- chlorothiophene. The predominant reaction: ac.-

In. accordance with. he present. invention.

cordingly was:-

with water.

hexachlorothiolene may be obtained by subjecting thiophene to complete chlorination in the presence of a catalyst of iodine and with or without the use of solvents such as chloroform, carbon tetrachloride, etc.

The chlorination reaction of the present invention will generally be carried out at a temperature varying between about C. and about 120 C., preferably at a temperature between about 40 C. and aboutflOf-Cxand a-reaction timesufficient tdfeffect a-complete chlorination of thio-' phene. The amount of iodine employed as cata lyst will be less than 0.5 mole per mole of thiophene reactant. Generally, minute amounts of iodine will be employed, usually in the range of from about .0005 to about 0.1 mole of iodine per Table I -I0dine in Grams of Heregrams per clilorothiolcnc Mole of per Mole of Thiophene Thiophcnc The following example will serve to illustrate the process of this invention without. limiting the same:

Example 1 Two hundred ten grams of thiophene (2.5 moles) and 10 grams of iodine were placed in a .l-liter flask equipped with a stirrer, a spiral-type condenser, a thermometer, and a chlorine inlet tube. Chlorine was bubbled through the thiophene-iodine mixture at a temperature of about 40 C. at such a rate as to require cooling of the flask to avoid an increase in temperature. After about one hour, the color of the iodine disappeared and the temperature was allowed to rise to 70-75 C. The temperature was maintained at TO-75 C. through cooling for about 4.5 hours. The product was washed with water and subsequently dissolved in benzene. The benzene solution was washed with a 5% aqueous solution of potassium carbonate, given two separate washes with a 5% aqueous solution of sodium thiosulfate. again Washed with a 5% solution of potassium carbonate, and finally given two separate washes The washed benzene solution was filtered and then dried over anhydrous sodium sulfate. The dried product was filtered and the solvent was removed on a steam bath. The product thus obtained was distilled under reduced pressure to yield 562 grams of hexachlorothiolene.

Example 2 :Twenty-flve andJ/m grams of thiophene (0.3

mole), 75 grams of chloroform (solvent), and 3 grams of iodine were placed in a 500-0. 0., threenecked flask equipped with a stirrer, a reflux condenser, a thermometer, and a chlorine inlet tube. Chlorine was bubbled into the flask for 50 minutes, at a rate to maintain a temperature of 40 C. At the end of 50 minutes, the temperature increased to 55-60 C. and remained at this level for a period of time of about 3 to 5 hours, at the end of which the temperature decreased, indicating that the reaction had been completed. The product was washed with water and then dissolved in ethyl ether. This solution was given two separate washes with water, two separate washes with a 5% aqueous solution of potassium carbonate, two separate washes with a 5% aqueous solution of sodium thiosulfate, another wash with a 5% aqueous solution of potassium carbonate, and finally another two separate washes with water. The washed ethyl ether solution was dried overnight over anhydrous sodium sulfate. The solvent was removed on a water bath and the product thus obtained was distilled under reduced pressure to yield an impure hexachlorothiolene. This impure product was redistilled to yield pure hexachlorothiolene, B. P. 90.5-91.5 C. at 2 mm., M. P. 40.5-41 C.

The process may be carried out as a batch, continuous or semi-continuous type of operation. For efhcient operation, whether the process is carried out on a batch or continuous basis, it is essential that the reactants be intimately contacted with one another in the presence of iodine. This may be achieved in several ways and in apparatus that are well known in the art.

Hexachlorothiolene, when added in minor proportions to lubricating oils, improves their extreme pressure characteristics. The amounts ordinarily added for this purpose will be between about 1 per cent and about 10 per cent by weight and, generally speaking, a sufficient amount wil. be added to improve the extreme pressure characteristics of a lubricating oil. The beneficial results obtained by adding varying amounts of hexachlorothiolene to gear oils may be shown by standard lubricant tests, such as the Alrnen' load test and the S. A. E. gear oil test. The Almen load test consists of placing a 30-gram sample of the lubricant to be tested in a small metal cup of the Almen test machine. The cup is provided with a A" drill rod shaft rotating ina split bushing at 600 revolutions per minute. Weights are added at ten-second intervals over a period of 5 minutes to a loading lever working to apply pressure on the split bushing. The Almen value is expressed as the number of weights. Each weight weighs 2 pounds and is equivalent to '1000 pounds per direction so as to produce a combination of rolling without a minor proportion of hexachlorothiolene are given below:

Table II Amount of s A E Almen Load Test Hcxachlorothiolene,

Per Cent by Scale Weight Wts. Torque None 3 Test specimen seized before test was completed. 3 460 6 17. 5 over 530 16 21.

lene which comprises contacting thiophene with L chlorine in the presence of a small amount less than 0.5 mole of iodine per mole of thiophene for a suflicient length of time to effect complete chlorination.

2. The process for producing hexachlorothiolene which comprises contacting thiophene with chlorine in the presence of between about .0005 and about 0.1 mole of iodine per mole of thiophene for a sufficient length of time to effect complete chlorination.

3. The process for producing hexachlcrothiolene which comprises contacting thiophene with chlorine at a temperature between about 0 C. and about 120 C. in the presence of a small amount less than 0.5 mole of iodine per mole of thiophene for a sufficient length of time to effect complete chlorination.

4. The process for producing hexachlorothiolene which comprises contacting thiophene with chlorine at a. temperature between about C. and about '7 0 C. in the presence of a small amount less than 0.5 mole of iodine per mole of thiophene for a suflicient length of time to effect complete chlorination.

5. The process for producing hexachlorothiolene, which comprises mixing thiophene and a small amount of less than 0.5 mole of iodine per mole of thiophene, bubbling chlorine through the thiophene-iodine mixture at a temperature in the range of 0-120" C. for a sufficient length of time to effect complete chlorination, removing unreacted iodine from the resulting reaction product mixture, neutralizing said product, and distilling the same to separate therefrom hexachlorothiolene.

6. The process for producing hexachlorothiolene, which comprises mixing thiophene and a small amount of less than 0.5 mole of iodine per mole of thiophene, bubbling chlorine through the thiophene-iodine mixture at such a rate that that the temperature is maintained within the range of 40 to C. until complete chlorination is effected, removing unreacted iodine from the resulting reaction product mixture, neutralizing said product and distilling the same to separate therefrom hexachlorothiolene.

7. As a new composition of matter, 2,23,45,5- hexachloro-3-thiolene HENRY D. NORRIS. JOHN H. MoCRACKEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,471,150 Dziewonski Oct. 16, 1923 2,208,161 Prutton July 16, 1940 2,410,401 Coffman Oct. 29, 1946 2,411,225 Patterson Nov. 19, 1946 OTHER REFERENCES Willgerodt: J. fiir Praktische Chemie, 33, 151 (1886).

Steinkopf: Ann. 532, 280 (1937).

Morton: The Chemistry of Heterocyclic Compounds, pages 42 and 43, McGraw-Hill, 1946.

Groggins: Unit Processes in Organic Synthesis, p. 183, McGraw-Hill, 1938.

Gilman: Organic Chemistry, vol. 1, ed. 2, p. 858, John Wiley, Inc., 1943.

Berichte, 18, 450-1 (1885).

Alles: J. Pharm. and Exp. Ther. '72, 265 (1941). 

7. AS A NEW COMPOSITION OF MATTER, 2,2,3,4,5,5HEXACHLORO-3-THIOLENE. 